Sensor storage container

ABSTRACT

A sensor storage container is provided that allows sensors to be checked visually from the outside. A container is used for storing sensors including an oxidation-reduction enzyme that oxidizes or reduces an object to be analyzed, a mediator that mediates the transfer of electrons caused by oxidation or reduction, and a detection means that detects the oxidation or reduction reaction. The container is transparent or semi-transparent in whole or in part and thereby the sensors can be checked visually from the outside of the container. This container may be composed of a container body and a lid. The container body may be provided with a scale. Preferably, the sensors are those produced using a ruthenium metal complex as the mediator.

TECHNICAL FIELD

The present invention relates to a sensor storage container that storessensors to be used for analyzing an object to be analyzed through anoxidation-reduction reaction.

BACKGROUND ART

Conventionally, sensors are used widely for analyzing biogenicsubstances such as glucose, cholesterol, etc. For instance, a glucosesensor is used for the self-control of a diabetic's blood-sugar level.Generally, the glucose sensor is an electrode sensor in which a workingelectrode and a reference electrode are formed on a substrate, andreagents such as glucose oxidase and potassium ferricyanide are providedthereon. When this electrode sensor is placed in a measuring device anda diabetic puts his blood collected by himself onto the reagent part,the glucose oxidase oxidizes the glucose contained in the blood to causeelectrons to be transferred and thereby the current value changes. Thechange in current value then is detected with the pair of electrodes andis measured with the measuring device to be converted into theblood-sugar level, which then is displayed. The potassium ferricyanidemediates the transfer of electrons caused through an oxidation-reductionreaction and thus is referred to as a mediator. This substance deliverselectrons to and receives electrons from the electrodes. This transferof electrons that occurs between the electrodes and the mediator iscarried out at high speed, which results in a higher measuring speed.The sensor is stored in a container as one of a plurality of sensors andis taken out when it is used.

The container for the sensors, however, is not transparent and thereforethe number of sensors cannot be checked visually from the outside.Accordingly, in order to check the number of sensors visually, it isnecessary to open the container, which is inconvenient. In addition, thesensors are exposed to the outside air every time the number of sensorsis checked visually, and this causes the sensors to deteriorate due tooxidization caused by or humidity brought by the air, which has been aproblem.

DISCLOSURE OF INVENTION

The present invention was made in consideration of the aforementionedsituations. An object of the present invention is to provide a sensorstorage container that makes it possible to check the number of sensorsvisually from the outside without opening the container.

In order to achieve the above-mentioned object, the container of thepresent invention is a sensor container for storing sensors and istransparent or semi-transparent in part or in whole.

The sensor storage container of the present invention makes it possibleto check the number of remaining sensors visually from the outside, andthus is not only convenient but also can prevent the sensors fromdeteriorating since the container is not opened every time the number ofsensors is checked visually.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing the configuration of an example of thecontainer according to the present invention.

FIG. 2 is a diagram showing the configuration of another example of thecontainer according to the present invention.

FIG. 3 is a cross-sectional view showing an example of the configurationof an electrode sensor.

FIG. 4 is a cross-sectional view showing an example of the configurationof a colorimetric sensor.

FIGS. 5A and 5B are a perspective view and a cross-sectional viewshowing another configuration of the container according to the presentinvention, respectively.

DESCRIPTION OF THE INVENTION

The type of sensors to be contained in the container of the presentinvention is not particularly limited and the sensors may have or maynot have lightfastness. When lightfast sensors are to be stored, thetransparent or semi-transparent part may be formed in any part of thecontainer.

In the present invention, the word “transparent” or “semi-transparent”denotes a property that allows the sensors contained in the container tobe checked visually from the outside.

When the sensors to be contained in the container of the presentinvention do not have lightfastness, it is preferable that only thebottom part of the container be transparent or semi-transparent. Thismakes it possible to see the sensors through the bottom part, only whenthe sensors are checked visually, and to prevent light from entering thecontainer at any other times, which further can prevent the sensors fromdeteriorating.

Preferably, the container of the present invention has a scale fordetermining the number of the sensors. This is because the number of thesensors can be checked visually correctly when the scale is provided.When only the bottom part of the container is transparent orsemi-transparent, it is more preferable that the container have thescale in its bottom part. The container of the present invention may becomposed of a container body and a lid.

The material of the container according to the present invention is notparticularly limited but a semi-transparent or transparent material isused for the semi-transparent or transparent part of the container.Examples of the semi-transparent material include bakelite, phenolresin, polyethylene, polysulfone, polycarbonate, ABS resin,polypropylene, vinyl chloride, epoxy resin, etc. Among thempolyethylene, polypropylene, and vinyl chloride are preferable, andpolyethylene and polypropylene are particularly preferable. Furthermore,the transparent material to be described below can be processed into asemi-transparent material through the addition of an additive such as apigment. Examples of the transparent material include acrylic resin,polycarbonate, polysulfone, ABS resin, polyethylene, polypropylene,vinyl chloride, epoxy resin, etc. Among them polyethylene,polypropylene, and vinyl chloride are preferable, and polypropylene isparticularly preferable.

Furthermore, an ultraviolet absorber may be added to the above-mentionedtransparent material. Examples of the ultraviolet absorber include2-(2′-hydroxy-5′-methylphenyl)benzotriazole,2-(2′-hydroxy-3′-t-butyl-5′-methylphenyl)-5-chlorobenzotriazole,2-(2′-hydroxy-3′5-di-t-butylphenyl)-5-chlorobenzotriazole,2-hydroxy-4-n-octoxy-benzophenone, phenyl salicylate, etc.

In the present invention, the transparent or semi-transparent materialdenotes one that allows the sensors to be checked visually from theoutside through the material.

In the container of the present invention, the transparent orsemi-transparent part may be colored. In that case, examples of thecolor of the container include black, gray, brown, blue, green, red,yellow, and white. The color is preferably black, gray, brown, blue, oryellow and more preferably black, gray, or brown. Such coloring makes itpossible to prevent sensors with poor lightfastness from deteriorating.

In the container of the present invention, the material of the partother than the transparent or semi-transparent part is not particularlylimited. For instance, the above-mentioned transparent orsemi-transparent materials can be used including bakelite, phenol resin,polyethylene, acrylic resin, polycarbonate, polysulfone, ABS resin,polypropylene, vinyl chloride, epoxy resin, etc.

The shape of the container of the present invention is not particularlylimited. Examples of the shape include a rectangular parallelepipedshape, a cubic shape, a columnar shape, an elliptic cylinder shape, etc.The shape is determined suitably according to various conditions such asthe shape, size, etc. of the sensors. The size of the container of thepresent invention also is not particularly limited but is determinedsuitably according to various conditions such as the shape, size, etc.of the sensors. For instance, when the container is of a rectangularparallelepiped shape, the size thereof is, for example, length 15 mm to50 mm×width 15 mm to 50 mm×height 30 mm to 100 mm, preferably length 20mm to 40 mm×width 20 mm to 40 mm×height 40 mm to 80 mm, and morepreferably length 30 mm to 35 mm×width 30 mm to 35 mm×height 45 mm to 55mm.

An example of the container of the present invention is shown in FIG. 1.As shown in FIG. 1, this sensor storage container 1 is composed of acontainer body 11 and a lid 12. The whole container body 11 issemi-transparent or transparent. The side face of the container body 11is provided with a scale 13 in the height direction. In FIG. 1, numeral14 indicates a plurality of sensors stored in the container. Inaddition, FIG. 2 shows an example in which the bottom part of thecontainer is provided with a scale. As shown in FIG. 2, the sensorstorage container 2 is composed of a container body 21 and a lid 22. Thewhole container body 21 is transparent or semi-transparent. Furthermore,the bottom part of the container body 21 has a scale. When the number ofthe sensors contained in this container is to be checked visually, thecontainer simply is laid on its side. In FIG. 2, numeral 24 indicates aplurality of sensors stored in the container.

FIGS. 5A and 5B show a perspective view and a cross-sectional view ofanother example of the container according to the present invention. Asshown in FIGS. 5A and 5B, the container 5 is composed of a containerbody 51 (transparent or semi-transparent), a top lid 52, and a bottomlid 54. The container body 51 has a circular opening 53 in the upperpart thereof A circular projection of the top lid 52 can fit into thecircular opening 53. Furthermore, the whole bottom part of the containerbody 51 is open and is closed with the bottom lid 54. This container 5also may be provided with a scale for visually checking the number ofthe sensors. The size of the container with such a shape is notparticularly limited but can be for instance, width 15 mm to 50mm×length 15 mm to 50 mm×height 30 mm to 100 mm, preferably width 20 mmto 40 mm×length 20 mm to 40 mm×height 40 mm to 80 mm, and morepreferably width 30 mm to 35 mm×length 30 mm to 35 mm×height 45 mm to 55mm.

The method of manufacturing a container according to the presentinvention is not particularly limited but it can be manufactured by thefollowing methods, for instance. Examples of the method of manufacturinga container that is transparent only in its bottom part include: amethod including producing a body part colored with a pigment having ashielding property and a transparent or semi-transparent bottom part byinjection molding as individual parts and then bonding them to eachother; a method including two-color-molding a body part and a bottompart by injection molding and then further molding the molded product bybiaxial stretching blow molding or the like; and a method includingproducing a container whose whole part is transparent orsemi-transparent and then attaching a colored shrink film to the wholepart except for the bottom part thereof. The bonding method is notparticularly limited but can be carried out by ultrasonic welding,thermal welding, etc. or using an adhesive, a solvent, etc., forexample. Among them the ultrasonic welding is preferable. Furthermore,the material of the shrink film is not particularly limited but can be,for instance, polyethylene, polypropylene, or vinyl chloride.

An example of the sensors to be stored in the container of the presentinvention is described next.

The sensors to be stored in the container of the present inventioninclude, for instance, an oxidation-reduction enzyme, a mediator thatmediates the transfer of electrons caused by oxidation or reduction, anda detection means that detects the oxidation-reduction reaction.

Preferably, the sensors have resistance to light (lightfastness).Examples of the specific means for providing the sensors with theresistance to light include using a lightfast transition metal complexas a mediator and using a shielding material as a composition materialof the sensors. Examples of the lightfast transition metal complexinclude a copper complex, an iron complex, a ruthenium complex, and anosmium complex. Among them the ruthenium complex is preferable. Thecopper complex, iron complex, ruthenium complex, and osmium complex aredescribed below in detail. The following complexes to be used herein canbe commercially available products or may be prepared by conventionallywell-known methods.

Copper Complex

A copper complex changes in color tone, for instance, from blue (Cu²⁺)to reddish brown (Cu⁺) through the transfer of electrons from an enzyme.Examples of the ligand of a copper complex include nitrogen containingligands such as bipyridine, imidazole, amino acid, phenanthroline,ethylenediamine, etc. The bipyridine, imidazole, amino acid,ethylenediamine, and phenanthroline may be combined into mixed ligands.

When the ligand is bipyridine, the coordination number thereof is 4 or6. From the viewpoint of stability, however, it is preferable that twobipyridines be coordinated. The bipyridines do not need to besubstituted but a substituent may be introduced. The introduction of thesubstituent makes it possible to adjust, for instance, solubility,oxidation-reduction potential, etc. The sites of substitution includesites 4,4′ and 5,5′. Examples of the substituents include: alkyl groupssuch as a methyl group, an ethyl group, a propyl group, etc.; aminegroups such as a phenyl group, an amino group, etc.; alkoxyl groups suchas a hydroxy group, a methoxy group, an ethoxy group, etc.; a carboxylgroup; and halogen groups such as bromine, chlorine, iodine, etc.

Examples of the bipyridine copper complex include [Cu(bipyridine)₂],[Cu(4,4′-dimethyl-2,2′-bipyridine)₂],[Cu(4,4′-diphenyl-2,2′-bipyridine)₂],[Cu(4,4′-diamino-2,2′-bipyridine)₂],[Cu(4,4′-dihydroxy-2,2′-bipyridine)₂],[Cu(4,4′-dicarboxy-2,2′-bipyridine)₂],[Cu(4,4′-dibromo-2,2′-bipyridine)₂],[Cu(5,5′-dimethyl-2,2′-bipyridine)₂],[Cu(5,5′-diphenyl-2,2′-bipyridine)₂],[Cu(5,5′-diamino-2,2′-bipyridine)₂],[Cu(5,5′-dihydroxy-2,2′-bipyridine)₂],[Cu(5,5′-dicarboxy-2,2′-bipyridine)₂],[Cu(5,5′-dibromo-2,2′-bipyridine)₂], [Cu(bipyridine)₃],[Cu(4,4′-dimethyl-2,2′-bipyridine)₃],[Cu(4,4′-diphenyl-2,2′-bipyridine)₃],[Cu(4,4′-diamino-2,2′-bipyridine)₃],[Cu(4,4′-dihydroxy-2,2′-bipyridine)₃],[Cu(4,4′-dicarboxy-2,2′-bipyridine)₃],[Cu(4,4′-dibromo-2,2′-bipyridine)₃],[Cu(5,5′-dimethyl-2,2′-bipyridine)₃],[Cu(5,5′-diphenyl-2,2′-bipyridine)₃],[Cu(5,5′-diamino-2,2′-bipyridine)₃],[Cu(5,5′-dihydroxy-2,2′-bipyridine)₃],[Cu(5,5′-dicarboxy-2,2′-bipyridine)₃],[Cu(5,5′-dibromo-2,2′-bipyridine)₃], etc.

When the ligand is imidazole, the coordination number thereof is 4.Imidazole does not need to be substituted but a substituent may beintroduced. The introduction of the substituent makes it possible toadjust, for instance, solubility, oxidation-reduction potential, etc.The sites of substitution include sites 2, 4, and 5. Examples of thesubstituents include: alkyl groups such as a methyl group, an ethylgroup, a propyl group, etc.; amine groups such as a phenyl group, anamino group, etc.; alkoxyl groups such as a hydroxy group, a methoxygroup, an ethoxy group, etc.; a carboxyl group; and halogen groups suchas bromine, chlorine, iodine, etc.

Examples of the imidazole copper complex include [Cu(imidazole)₄],[Cu(4-methyl-imidazole)₄], [Cu(4-phenyl-imidazole)₄],[Cu(4-amino-imidazole)₄], [Cu(4-hydroxy-imidazole)₄],[Cu(4-carboxy-imidazole)₄], [Cu(4-bromo-imidazole)₄], etc.

The amino acid is arginine (L-Arg), for instance. An arginine coppercomplex has the advantage of high solubility. Furthermore, examples ofthe mixed ligands include a combination of bipyridine and imidazole anda combination of bipyridine and amino acid, specifically[Cu(imidazole)₂(bipyridine)] and [Cu(L-Arg)₂(bipyridine)]. The use of amixed ligand allows the copper complex to be provided with variouscharacteristics. For instance, the use of arginine improves thesolubility of the complex.

Iron Complex

An iron complex changes in color tone, for instance, from a yellowishcolor (Fe³⁺) to a reddish color (Fe²⁺) through the transfer of electronsfrom an enzyme. Examples of the ligand of an iron complex includenitrogen containing ligands such as bipyridine, imidazole, amino acid,phenanthroline, ethylenediamine, etc. The bipyridine, imidazole, aminoacid, phenanthroline, and ethylenediamine may be combined into mixedligands.

When the ligand is bipyridine, the coordination number thereof is 6. Thebipyridine does not need to be substituted but a substituent may beintroduced. The introduction of the substituent makes it possible toadjust, for instance, solubility, oxidation-reduction potential, etc.The sites of substitution include sites 4,4′ and 5,5′. Examples of thesubstituent include: alkyl groups such as a methyl group, an ethylgroup, a propyl group, etc.; amine groups such as a phenyl group, anamino group, etc.; alkoxyl groups such as a hydroxy group, a methoxygroup, an ethoxy group, etc.; a carboxyl group; and halogen groups suchas bromine, chlorine, iodine, etc.

Examples of the bipyridine iron complex include [Fe(bipyridine)₃],[Fe(4,4′-dimethyl-2,2′-bipyridine)₃],[Fe(4,4′-diphenyl-2,2′-bipyridine)₃],[Fe(4,4′-diamino-2,2′-bipyridine)₃],[Fe(4,4′-dihydroxy-2,2′-bipyridine)₃],[Fe(4,4′-dicarboxy-2,2′-bipyridine)₃],[Fe(4,4′-dibromo-2,2′-bipyridine)₃],[Fe(5,5′-dimethyl-2,2′-bipyridine)₃],[Fe(5,5′-diphenyl-2,2′-bipyridine)₃],[Fe(5,5′-diamino-2,2′-bipyridine)₃],[Fe(5,5′-dihydroxy-2,2′-bipyridine)₃],[Fe(5,5′-dicarboxy-2,2′-bipyridine)₃],[Fe(5,5′-dibromo-2,2′-bipyridine)₃], etc.

When the ligand is imidazole, the coordination number thereof is 6.Imidazole does not need to be substituted but a substituent may beintroduced. The introduction of the substituent makes it possible toadjust, for instance, solubility, oxidation-reduction potential, etc.The sites of substitution include sites 2, 4, and 5. Examples of thesubstituent include: alkyl groups such as a methyl group, an ethylgroup, a propyl group, etc.; amine groups such as a phenyl group, anamino group, etc.; alkoxyl groups such as a hydroxy group, a methoxygroup, an ethoxy group, etc.; a carboxyl group; and halogen groups suchas bromine, chlorine, iodine, etc.

Examples of the imidazole iron complex include [Fe(imidazole)₆],[Fe(4-methyl-imidazole)₆], [Fe(4-phenyl-imidazole)₆],[Fe(4-amino-imidazole)₆], [Fe(4-hydroxy-imidazole)₆],[Fe(4-carboxy-imidazole)₆], [Fe(4-bromo-imidazole)₆], etc.

The amino acid is arginine (L-Arg), for instance. An arginine ironcomplex generally has the advantage of high solubility. Furthermore,examples of the mixed ligands include a combination of bipyridine andimidazole and a combination of bipyridine and amino acid, specifically[Fe(imidazole)₂(bipyridine)₂] and [Fe(L-Arg)₂(bipyridine)₂]. The use ofa mixed ligand allows the complex to be provided with variouscharacteristics. For instance, the use of arginine improves thesolubility of the complex.

Ruthenium Complex

Examples of the ligand of a ruthenium complex include nitrogencontaining ligands such as bipyridine, imidazole, amino acid,phenanthroline, ethylenediamine, etc. The bipyridine, imidazole, aminoacid, phenanthroline, and ethylenediamine may be combined into mixedligands.

When the ligand is bipyridine, the coordination number thereof is 6. Thebipyridine does not need to be substituted but a substituent may beintroduced. The introduction of the substituent makes it possible toadjust, for instance, solubility, oxidation-reduction potential, etc.The sites of substitution include sites 4,4′ and 5,5′. Examples of thesubstituent include: alkyl groups such as a methyl group, an ethylgroup, a propyl group, etc.; amine groups such as a phenyl group, anamino group, etc.; alkoxyl groups such as a hydroxy group, a methoxygroup, an ethoxy group, etc.; a carboxyl group; and halogen groups suchas bromine, chlorine, iodine, etc.

Examples of the bipyridine ruthenium complex include [Ru(bipyridine)₃],[Ru(4,4′-dimethyl-2,2′-bipyridine)₃],[Ru(4,4′-diphenyl-2,2′-bipyridine)₃],[Ru(4,4′-diamino-2,2′-bipyridine)₃],[Ru(4,4′-dihydroxy-2,2′-bipyridine)₃],[Ru(4,4′-dicarboxy-2,2′-bipyridine)₃],[Ru(4,4′-dibromo-2,2′-bipyridine)₃],[Ru(5,5′-dimethyl-2,2′-bipyridine)₃],[Ru(5,5′-diphenyl-2,2′-bipyridine)₃],[Ru(5,5′-diamino-2,2′-bipyridine)₃],[Ru(5,5′-dihydroxy-2,2′-bipyridine)₃],[Ru(5,5′-dicarboxy-2,2′-bipyridine)₃],[Ru(5,5′-dibromo-2,2′-bipyridine)₃], etc.

When the ligand is imidazole, the coordination number thereof is 6.Imidazole does not need to be substituted but a substituent may beintroduced. The introduction of the substituent makes it possible toadjust, for instance, solubility, oxidation-reduction potential, etc.The sites of substitution include sites 2, 4, and 5. Examples of thesubstituent include: alkyl groups such as a methyl group, an ethylgroup, a propyl group, etc.; amine groups such as a phenyl group, anamino group, etc.; alkoxyl groups such as a hydroxy group, a methoxygroup, an ethoxy group, etc.; a carboxyl group; and halogen groups suchas bromine, chlorine, iodine, etc.

Examples of the imidazole ruthenium complex include [Ru(imidazole)₆],[Ru(4-methyl-imidazole)₆], [Ru(4-phenyl-imidazole)₆],[Ru(4-amino-imidazole)₆], [Ru(4-hydroxy-imidazole)₆],[Ru(4-carboxy-imidazole)₆], [Ru(4-bromo-imidazole)₆], etc.

The amino acid is arginine (L-Arg), for instance. An arginine rutheniumcomplex has the advantage of high solubility. Furthermore, examples ofthe mixed ligands include a combination of bipyridine and imidazole anda combination of bipyridine and amino acid, specifically[Ru(imidazole)₂(bipyridine)₂] and [Ru(L-Arg)₂(bipyridine)₂]. The use ofa mixed ligand allows the complex to be provided with variouscharacteristics. For instance, the use of arginine improves thesolubility of the complex.

The oxidation-reduction enzyme to be used for the sensors is notparticularly limited but is determined suitably according to themeasurement objective. Examples of the oxidation-reduction enzymeinclude glucose oxidase, glucose dehydrogenase, lactate dehydrogenase,cholesterol oxidase, etc.

The means of detecting the oxidation-reduction reaction of the sensorsis not particularly limited. For example, in the case of an electrodesensor, the means of detecting the oxidation-reduction reaction iselectrodes that detect the current produced by the oxidation orreduction of the mediator. On the other hand, in the case of acolorimetric sensor, the means of detecting the oxidation-reductionreaction is a pigment that is colored by the oxidation or reduction.

The configuration of the sensors is not particularly limited but acommon configuration may be employed.

FIG. 3 shows an example of the basic configuration of the electrodesensor. As shown in FIG. 3, in this electrode sensor 3, a pair ofelectrodes (a working pole 32 and a reference pole 33) is formed on asubstrate 31, and a reagent layer including an oxidation-reductionenzyme and a mediator is formed thereon. This electrode sensor is storedin the container of the present invention and is taken out to be placedin a measuring device when it is used. Then a measuring object sample isallowed to adhere to the reagent layer 34 and thereby theoxidation-reduction enzyme causes an oxidation-reduction reaction. Thisis detected with the electrodes 32 and 33 as a change in current valueand is converted into a predetermined constituent concentration by themeasuring device, which then is displayed.

FIG. 4 shows an example of the basic configuration of the colorimetricsensor. As shown in FIG. 4, in this colorimetric sensor 4, a reagentlayer 42 including an oxidation-reduction enzyme, a color former (thesubstrate of the enzyme), and a mediator is formed on a substrate 41.This colorimetric sensor is taken out of the container of the presentinvention when it is used. Then a measuring object sample is allowed toadhere to the reagent layer 42 and thereby the oxidation-reductionenzyme causes an oxidation-reduction reaction, which results in coloringof the color former. The degree of this coloring is measured with anoptical measuring apparatus such as a spectrophotometer and then isconverted into a predetermined constituent concentration.

In the sensors described above, the reagent layers 34 and 42 may containother components, for instance, hydrophilic polymers, a buffer, astabilizer, etc.

EXAMPLES

Examples of the present invention are described next.

Example 1 Transparent Container

A container shown in FIGS. 5A and 5B that was transparent in whole wasproduced by injection molding using polypropylene as a material. Thewhole container has a size of width 20 mm×length 40 mm×height 55 mm. Theupper circular opening has an inner diameter of 16 mm.

Container that is Transparent Only in its Bottom Part

A container shown in FIGS. 5A and 5B that was transparent only in itsbottom part was produced by forming a body part having a shieldingproperty and the transparent bottom part separately by injection moldingusing polypropylene as a material and then bonding them to each other byultrasonic welding. The whole container has a size of width 20 mm×length40 mm×height 55 mm. The upper circular opening has an inner diameter of16 mm.

A glucose electrode sensor including a ruthenium complex used as amediator or a glucose electrode sensor including potassium ferricyanideused as a mediator was placed in the transparent container and thecontainer that was transparent only in its bottom part, which then wereallowed to stand in a room for four days. Thereafter, the concentrationsof the glucose solutions were measured. Furthermore, both theabove-mentioned sensors were placed in shielding bottles that were usedas controls, and the concentrations of the glucose solutions weremeasured in the same manner as above. These results are indicated inTables 2 to 5 below. The container that was transparent only in itsbottom part was allowed to stand still the bottom part down. Both theelectrode sensors were produced by the following method. Theconcentrations of the glucose solutions were measured under thefollowing conditions.

Production of Glucose Electrode Sensor

A glucose electrode sensor was produced that included a first electrode,a second electrode, a reagent layer, and a capillary that were formed ona substrate. The first electrode and the second electrode were formed byscreen-printing them on the substrate with carbon ink and then dryingthem. The capacity of the capillary was set at 0.3 μL. The reagent layerhad a two-layer structure composed of an electron transfer layer (amediator layer) and an enzyme containing layer. The electron transferlayer was formed by applying 0.4 μL of a first material solutionincluding an electron transfer material (the mediator: a rutheniumcomplex or potassium ferricyanide) to the substrate and then drying itthrough air blasting (at 30° C. and a relative humidity of 10%). Theenzyme containing layer was formed by applying 0.3 μL of a secondmaterial solution including an oxidation-reduction enzyme to theelectron transfer layer and then drying it through air blasting (at 30°C. and a relative humidity of 10%).

The first material solution was prepared as follows. That is, a liquidmixture obtained by mixing the materials (1) to (4), which are indicatedin Table 1 below, together in the order of the numbers was allowed tostand for one to three days and then an electron transfer material wasadded thereto. The second material solution was prepared by dissolvingan oxidation-reduction enzyme in 0.1% CHAPS.

TABLE 1 Composition of First Material Solution (Except for ElectronTransfer Material) (1)SWN (2)CHAPS (4)ACES Solution Solution SolutionConcen- Concen- (3)Distilled Concen- tration Amount tration Amount Watertration Amount 1.2% 250 μL 10% 25 μL 225 μL 200 mM 500 μL

In Table 1, “SWN” denotes Lucentite, “CHAPS” indicates3-[(3-choamidopropyl)dimethylammonio]-1-propanesulfonate, and “ACES”denotes N-(2-acetamido)-2-aminoethanesulfonic acid. The SWN used hereinwas a product No. 3150 manufactured by CO-OP CHEMICAL CO., LTD. TheCHAPS and ACES used herein were products Nos. KC062 and ED067manufactured by DOJINDO LABORATORIES. The ACES solution was prepared soas to have a pH of 7.5.

The ruthenium (Ru) complex used herein was [Ru(NH₃)₆]Cl₃ (LM722,manufactured by DOJINDO LABORATORIES). The potassium ferricyanide(K₃[Fe(III)(CN)₆]) used herein was a product No. 28637-75 manufacturedby Nacalai Tesque, Inc. The oxidation-reduction enzyme used herein wasCyGDH. The CyGDH is composed of an alpha subunit, a beta subunit, and agamma subunit.

Measurement of Glucose Solution Concentration

The electrode sensor was placed in a measuring device (a tester). Twotypes of glucose solutions whose concentrations were 0 mg/dL (deciliter)and 600 mg/dL were subjected to the measurement. The measured valueswere current values (μA) obtained 10 seconds after the application ofconstant potential (200 mV) to the electrodes.

TABLE 2 Glucose Concentration: 0 mg/dL Sensors produced using Ru ComplexContainer that was Transparent transparent only in Container its bottompart Shielding Bottle Samples (μA) (μA) (μA) 1 0.17 0.16 0.21 2 0.190.18 0.14 AVG 0.18 0.17 0.17 SD 0.01 0.01 0.03 CV(%) 5.94 8.32 19.67

TABLE 3 Glucose Concentration: 600 mg/dL Sensors produced using RuComplex Container that was Transparent transparent only in Container itsbottom part Shielding Bottle Samples (μA) (μA) (μA) 1 9.83 9.43 9.76 29.24 9.60 9.97 3 9.35 9.40 9.22 4 9.53 9.59 AVG 9.48 9.49 9.64 SD 0.260.09 0.27 CV(%) 2.71 0.97 2.84

TABLE 4 Glucose Concentration: 0 mg/dL Sensors produced using potassiumferricyanide Container that was Transparent transparent only inContainer its bottom part Shielding Bottle Samples (μA) (μA) (μA) 1 8.682.16 1.76 2 9.72 2.05 1.99 3 8.89 2.30 1.59 AVG 9.10 2.17 1.78 SD 0.450.13 0.16 CV(%) 4.93 5.77 9.15

TABLE 5 Glucose Concentration: 600 mg/dL Sensors produced usingpotassium ferricyanide Container that was Transparent transparent onlyin Container its bottom part Shielding Bottle Samples (μA) (μA) (μA) 118.38 11.01 11.67 2 14.27 11.95 11.98 3 20.19 11.25 11.06 AVG 17.6111.40 11.57 SD 2.48 0.40 0.38 CV(%) 14.08 3.50 3.30

As shown in Tables 2 to 5, when the electrode sensors produced usingpotassium ferricyanide were placed in the transparent container and thenwere allowed to stand in a room for four days, the potassiumferricyanide turned into potassium ferrocyanide due to light and therebya considerable increase in background current (current obtained when theglucose concentration was 0 mg/dL) was observed. This means that anerror as high as +50% is caused when being indicated in terms of theglucose concentration. When the electrode sensors were placed in thecontainer that was transparent only in its bottom part and then wereallowed to stand, no increase in background current was observed. Thusthe measurement was carried out correctly, with no errors being caused,and less variations in measured value resulted. On the other hand, inthe case of the electrode sensors produced using a ruthenium complex,even when they were placed in the transparent container and then wereallowed to stand, no increase in background current was observed. Thusthe measurement was carried out correctly, with no errors being caused,and less variations in measured value resulted.

Example 2

Two types of containers were produced as follows. Using them, theconcentrations of glucose solutions were measured in the same manner asin Example 1. The results are indicated in Tables 6 to 9 below.

Semi-Transparent Only in Bottom Part

A container shown in FIGS. 6A and 5B that was semi-transparent only inits bottom part was produced using polypropylene as a material in thesame manner as that employed for producing the container that wastransparent only in its bottom part. In producing the bottom part, colorpellets that were toned to deeper black were prepared first using apigment (carbon black) (the ratio of the pigment contained in thepellets: 20 wt. %). The color pellets thus prepared and achromatic colorpellets were mixed together at a mixing ratio of 5:100 so as to reach acritical point up to which the number of sensors can be checkedvisually. This was used to produce the bottom part. The whole containerhas a size of width 20 mm×length 40 mm×height 55 mm. The upper circularopening has an inner diameter of 16 mm.

Transparent Only in Bottom Part (Including an Ultraviolet Absorber AddedThereto)

A container shown in FIGS. 5A and 5B that was transparent only in itsbottom part (including an ultraviolet absorber added thereto) wasproduced using polypropylene as a material in the same manner as thatemployed for producing the container that was transparent only in itsbottom part. The material used for the bottom was that obtained byadding 2(2′-hydroxy-5′-methylphenyl)benzotriazole (3 wt. %) to theabove-mentioned material. The whole container has a size of width 20mm×length 40 mm×height 55 mm. The upper circular opening has an innerdiameter of 16 mm.

TABLE 6 Glucose Concentration: 0 mg/dL Sensors produced using Ru ComplexTransparent only in Bottom Part Semi-Transparent (including only inBottom Ultraviolet Part Absorber) Samples (μA) (μA) 1 0.19 0.17 2 0.180.18 AVG 0.19 0.18 SD 0.01 0.01 CV(%) 3.82 4.04

TABLE 7 Glucose Concentration: 600 mg/dL Sensors produced using RuComplex Transparent only in Bottom Part Semi-Transparent (including onlyin Bottom Ultraviolet Part Absorber) Samples (μA) (μA) 1 9.71 9.24 29.28 9.85 3 9.46 9.46 4 9.6 9.53 AVG 9.51 9.52 SD 0.19 0.25 CV(%) 1.952.65

TABLE 8 Glucose Concentration: 0 mg/dL Sensors produced using PotassiumFerricyanide Transparent only in Bottom Part Semi-Transparent (includingonly in Bottom Ultraviolet Part Absorber) Samples (μA) (μA) 1 2.13 1.972 1.86 2.07 3 2.1 2.34 AVG 2.03 2.13 SD 0.15 0.19 CV(%) 7.29 9.00

TABLE 9 Glucose Concentration: 600 mg/dL Sensors produced usingPotassium Ferricyanide Transparent only in Bottom Part Semi-Transparent(including only in Bottom Ultraviolet Part Absorber) Samples (μA) (μA) 112.32 11.86 2 11.98 12.11 2 11.22 11.03 AVG 11.84 11.67 SD 0.46 0.40CV(%) 3.88 3.90

As shown in Tables 6 to 9, no increases in background current of thesensors produced using potassium ferricyanide and the sensors producedusing a ruthenium complex were observed in either of the containers.Thus the measurement was carried out correctly, with no errors beingcaused, and less variations in measured value resulted.

INDUSTRIAL APPLICABILITY

The container of the present invention allows the numbers of remainingsensors to be checked visually from the outside and thus is convenient.

1. A sensor-container combination comprising a transparent orsemi-transparent container comprising at least one of polypropylene andpolyethylene, wherein the container comprises a container body, a lidand a bottom part; and a plurality of unshielded sensors stored in thecontainer, wherein the sensors each include an oxidation-reductionenzyme; a ruthenium complex; and a means for detecting changes incurrent resulting from action of the oxidation-reduction enzyme.
 2. Thesensor-container combination according to claim 1, wherein the containerhas a scale for determining the number of the sensors in the container.3. The sensor-container combination according to claim 1, wherein thesensors have lightfastness.
 4. The sensor-container combinationaccording to claim 1, wherein the detection means is electrodes thatdetect current produced by oxidation or reduction of the rutheniumcomplex, and the sensors are electrode sensors.
 5. The sensor-containercombination according to claim 1, wherein the detection means is asubstrate of the oxidation-reduction enzyme that colors throughoxidation or reduction, and the sensors are colorimetric sensors.
 6. Thesensor-containing combination according to claim 1, wherein thecontainer body has a circular opening, the lid has a circularprojection, and the circular projection of the lid is capable of fittinginto the circular opening of the container body.
 7. The sensor-containercombination according to claim 1, wherein the container body and the lidare connected to each other with a hinge.
 8. The sensor-containercombination according to claim 1, wherein a color of the bottom part ofthe container is selected from the group consisting of black, gray,brown, blue, green, red, yellow, and white.